What Is a 499 Status Code?

A non-standard status code introduced by nginx for the case when a client closes the connection while nginx is processing the request.

The HTTP 499 status code is not a standard HTTP status code, meaning it is not defined in the HTTP/1.1 specification. This status code is used by the nginx web server to indicate that the client closed the connection before the server could send a response.

The HTTP 499 error typically occurs when a client terminates the connection before the server is able to respond, such as when a user cancels a request or navigates away from a page before it fully loads. In some cases, the error may be caused by a misconfigured server or network issue that disrupts the connection between the client and server.

499 status code example

A 499 status code is not an officially recognized HTTP status code, but it is sometimes used by servers to indicate that a client has closed the connection without receiving a response. Here’s an example of a request and response:

Request

GET /index.html HTTP/1.1
Host: example.com

Response

HTTP/1.1 499 Client Closed Request
Server: nginx/1.19.6

Root causes of a 499 Status Code

The HTTP 499 error is specific to the nginx web server, and it occurs when the client closes the connection before the server can send a response. There are a number of reasons why this could happen, including:

Network issues:
If there is a problem with the network connection between the client and server, such as a dropped connection or high latency, the connection may be lost before the server can respond.

Client-side issues:
If the client navigates away from the page before it fully loads, or cancels the request before the server can respond, the connection may be terminated before a response is received.

Server-side issues:
If the server is experiencing issues, such as a high load or a misconfiguration, it may be unable to respond to the client’s request in a timely manner.

Firewall or security software:
If there is a firewall or security software in place that is blocking the connection or interfering with the communication between the client and server, the connection may be lost.

Misconfigured server:
If the server is misconfigured, it may not be able to properly handle requests and may result in a 499 error.

Server-side timeout:
The server may have a configuration that sets a timeout period for the response, and if it exceeds the limit, it may close the connection and result in a 499 error.

These are just a few examples of what could cause an HTTP 499 error. In order to determine the specific cause of the error, it may be necessary to investigate further using server logs or other troubleshooting methods.

Troubleshooting a 499 Status Code

Since the HTTP 499 error is not a standard HTTP status code, it can be tricky to troubleshoot. However, there are a few general steps that you can take to try to identify and resolve the issue:

• Check the server logs

If you have access to the server logs, check to see if there are any entries that correspond to the time that the HTTP 499 error occurred. This may provide clues as to what caused the error.

• Check the network connection

Verify that the network connection between the client and server is stable and reliable. Check for any network issues, such as dropped packets or high latency, which could cause the connection to be lost.

• Check the browser cache

Clear the browser cache and cookies to ensure that the error is not caused by a cached resource or cookie.

• Disable browser extensions

Disable any browser extensions that could be interfering with the connection, such as ad blockers or security software.

• Try a different browser or device

If the error persists, try accessing the site from a different browser or device to see if the issue is specific to the current configuration.

Does a 499 status code affect SEO?

Since a 499 status code is not an officially recognized HTTP status code and is not a common error, it is unlikely to have any direct impact on SEO. However, if it is a persistent issue on your website, it could affect user experience and lead to lower engagement and higher bounce rates, which could indirectly impact your SEO.

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